Feeding mechanism for sewing machines



Oct. 18, 1932. DYKEMAN 1,883,633

' FEEDING MECHANISM FOR SEWING MACHINES Filed Jan. 2, 1930 2 Sheets-Sheet l Oct. 18, 1932. H. E. DYKEMAN 1,883,633

FEEDING MECHANISM FOR SEWING MACHINES led Jail. 2, 1930 2 Sheets-Sheet 2 Patented Oct. 18, 1932 n me stares rArsNr orries HARRY E. DYKEMAN, CHICAGO, ILLINOIS, .ASSIGNOR T UNIONSPECIAL MACHINE COMPANY, OF OHICAGO, ILLINOIS, A CORPORATION 'OF ILLINOIS nnnnme ivrnonnnrsnz non snwina MACHINES Application filed January 2, 1930. Serial No. 418,127.

The invention relates to new and useful improvements in sewing machines, and more particularly to the feeding mechanism for a sewing machine.

' An object of the invention is toprovide a feeding mechanism for sewing machines which may be used for stitching wall-board,

table pads and similar stifl articles and turning thesame so as to cause the line of stitching a: to change its direction.

In the drawings which show by way ofillustration one embodiment of the inven tion:

Figure 1 is a front View of a portion of a 3'; machine embodying the improvements.

' portion of the feed dog.

:- anism for sewing machines which is especially 1 binding strip to a stiff heavy material.

adapted for feeding stiff materials, such as wall-board, table pads .and the like to a stitching mechanism. The feeding mechanism is particularly adapted for the applying of a The feed dog is provided with a material engaging section which lies alongside of the needle and which feeds the heavy material. The feed dog also has a section in rear of the needle which engages the binding for feeding the binding strip and the material to which it is joined. In turning sharp corners with this heavy material the stitching threads have been likely to catch on the side ofthe a feed dog which prevents proper stitch formastitching threads when the material is swung tion and often breaks the thread.

In the present inventionthe feed dog is constructed so as to avoid any possibility of the feed dog catching the binding strip or the sharply to the left as viewed by the operator for the purpose of rounding a corner. The feed dog is provided with the usual feed teeth Which slant rearwardly for engaging and 50 moving the material. The feed teeth in the region of the needle both in front, alongside and slightly in rear thereof are beveled OE and inclined from the base of the tooth toward the upper end of 'the'tooth at the far side of the feed dog. This inclining of the teeth away from the needleinsuresthat'the binding strip will slide up the inclined teeth without being caught and likewise the stitches will slide up the inclined teeth without being caught.

Referring more in detail to the drawings,

the sewing machine includes a supporting bed 1 on which is mounted awork support 2. The bed carrieslan overhanging arm 3 provided with a needle head 4 in which a needle bar 5 reciprocates. The needle-bar carries a needle :6. Cooperating with the needle 6beneath the work support is a'looper 7.. These parts are of the usual construction, The fabric is fed across the work support by a feeding mechanism which includes a feed .bar 8 pivoted at 9 to a feed rocker 10.

Said feed rocker'is oscillated by means 'of' a link 11 connected to the usual crank on the end of the main shaft 12. The feed bar is raised and lowered by an eccentric 13 on said main shaft 12; Mounted on this feed bar is my improved feed dog 14.

The feed dog includes a feeding section 15 which is located in rear of the needle 6 and a feeding section 16 which extends along: side of the needle from a point well in advance thereof to a point in line with the rear end of the section 15. The material is held on the work .support'by a presser foot 17 carried by a presser bar 18. A binding strip is led through a guide 19 of the English binder type and is foldedabout the edge of the material being stitched.

In Fig. 5 the material is. indicated at 20 and the binding. strip at 21. The binding strip is secured to the material by a line of stitching indicated at 22 insaid figure.

In turning the material so as to stitch about sharply rounded corners, a great deal of trouble has been experienced in the edge 23 of the binding strip engaging the side of the teeth ofthe feeding section 16 which would prevent the turning of the material. Again, the stitching threads between needle iii punctures on the under side of the material have caught on the teeth of the feed dog and either prevented a proper stitch formation or broken the stitching threads.

In order to prevent this interference of the feed dog section alongside of the needle with the free turning of the material being stitched, the teeth of the feed dog have been given a special construction. As shown in Figs. 2, 3 and 4 of the drawings the feeding section 16 is provided with teeth 24, 24 which extend all the way across the feeding section and which incline rearwardly on the front face thereof, thus providing relatively sharp material engaging edges 25, 25. These edges are preferable provided with V-shaped notches, thus producing in each tooth a series of projecting cutting or piercing points. The feed teeth are all similar in construction except the three feed teeth 24a alongside of the needle. The center one of these three teeth is directly alongside of the needle, while the front tooth 24a is slightly in ad Vance of the needle, and the rear tooth 24a is slightly in rear of the needle. The position of the needle is indicated at 6 in Fig. 3.

Each tooth 24a is provided with an inclined face 246. Said face inclines from the side of the feed dog adjacent the needle upwardly to the other side of the feed dog. The height of this tooth 24a is slightly less than the height of the feed teeth 24 of the feed dog. The face of each feed tooth 24 on the side thereof adjacent the needle is also inclined upwardly and outwardly for a short distance as indicated at 240. By inclining the feed teeth in the manner described it will be noted that when the material is turned for changing the direction of stitching .so as to pass about a rounded or square corner, the under edge 23 of the binding strip will slide up the inclined face 24?; and also slide up the inclined faces 24c and will not be caught by the feeding section. Likewise the stitching threads will slide up these inclined faces and pass over the feed dog without being caught thereby. When the material is turned, it is turned about the needle as a center and it is the edge of the binding strip and the stitches immediately in rear of the needle which have heretofore been caught by the feed dog section and which by the present form of feed dog will slide up these inclined faces. The feed dog, therefore, does not in any way interfere with the turning of the material for the stitching about sharply rounded corners.

It will be understood, of course, that the shaping of the feed dog teeth may be varied from that described above; the essential feature, however, consists in the shaping of the feed dog teeth adjacent the needle so that both the binding and stitching threads may slip readily over the feed dog when the material is turned without being caught thereby.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent, is

l. The combination of a stitch forming mechan sm includinga needle, a work sup port, and a feeding mechanism including a feed dog having a feeding section extending alongside of said needle, said feeding section having the teeth thereof in the region of the needle shaped so as to cause the stitching threads to readily slide onto and over the teeth of the feeding section when stitching about corners.

2. The combination of a stitch forming mechanism including a needle, a. work support, and a feeding mechanism including a feed dog having a feeding section extending alongside of the needle, said feeding section having upwardly and rearwardly projecting teeth, said teeth in the region adjacent the needle having their upper portions inclined from the bases of the teeth adjacent the needle, upwardly to the outer side of the section whereby the stitching threads will readily slide onto and over the teeth of the feeding section when stitching about corners.

3. The combination of .a stitch forming mechan sm including a needle, a work support, a binder for directing a binding strip about the edge of the material being stitched, and a feeding mechanism including a feed dog having a feeding section disposed in rear of the needle and a feeding section extending alongside of said needle, said feeding section alongside of the needle having upwardly and rearwardly projecting teeth, each tooth at the side of the feeding section adjacent the needle being inclined upwardly and outwardly toward the out-er side of the section whereby the edge of the binding strip and the stitching threads on the under side of the material will slide freely onto and over the teeth of the feeding section when stitching about corners. 7

In testimony whereof, I aii'ix my signature.

HARRY DYKEMAN. 

